This invention relates generally to waste disposal systems. More particularly, this invention relates to a separator for a food waste disposal system that separates liquids from solids.
Food waste disposal typically involves shattering food waste in the presence of water to yield a slurry that is drained to a sewer or is otherwise disposed of. Disposal by sewer is economically disadvantageous and wasteful of water. Disposal of the slurry by other methods likewise involves considerable expense due primarily to the weight of the water included with the solids. In accordance with the invention, there is provided a system for disposing food waste that enables conservation of water and reduction in solids volume.
With regard to the foregoing and other objects, the present invention is directed to a food waste disposal system having a separator for separating food waste solids from liquids.
In a preferred embodiment, the separator includes an elongate housing disposed at a predetermined angle relative to horizontal, a waste inlet, a liquid outlet and a waste outlet each in flow communication with the interior and exterior of the housing. A stationary elongate liquid permeable screen is disposed within the housing and has a length axis substantially aligned with the length of the housing. A conduit is in flow communication with the waste inlet and an interior portion of the screen for introducing food waste solids and liquids into the interior of the screen, and a rotatable screw conveyor having a shaft and a helical blade is provided for conveying the introduced food waste solids in a desired direction is disposed within the screen and substantially aligned with the length of the screen.
A cone member is mounted on the shaft of the rotatable screw adjacent a terminal end of the helical blade and is adjustably positionable between first and second positions on the shaft. A substantially solid member having an aperture therein for insertion of the shaft therethrough is located within the housing adjacent the terminal end of the helical blade to define an impedance to the passage of food waste solids. The aperture is positioned adjacent the cone member and spaced apart from the cone member to define a passage between the cone member and the aperture for the travel of food waste solids to the waste outlet, with the dimension of the passage corresponding to the position of the cone member on the shaft. A spring urges the cone member toward the terminal end of the helical blade.
During operation of the separator the screw conveyor urges waste solids against the cone member to compact the solids and force liquids from the solids and when the urging action of the waste solids against the cone member exceeds the counter-urging of the spring against the cone member. The cone member travels away from the terminal end of the helical blade thereby increasing the size of the passage between the cone member and the aperture. The cone member returns back toward the terminal end of the helical blade when the urging action of the waste solids decreases below that of the spring against the cone member.